I am learning XSLT and I came to an aspect of XSLT/XPath which is not clear to me.
I want to check if there is at least one element namePart with a value inside.
There can be something like this in XML:
<mods:name type="personal">
<mods:namePart type="family">Salamonis</mods:namePart>
<mods:namePart type="given"/>
</mods:name>
But also this due to any reason:
<mods:name type="personal">
<mods:namePart/>
</mods:name>
I think I have found out the solution for my problem. Actually I found two similar solutions but I do not understand the difference:
first:
<xsl:for-each select="mods:name">
<xsl:if test="mods:namePart/text() != ''"> ..... </xsl:if>
<xsl:for-each>
second:
<xsl:for-each select="mods:name">
<xsl:if test="mods:namePart[text() != '']"> ..... </xsl:if>
<xsl:for-each>
Apparently, both of them are working fine. But I am still thinking what is better to use or if there are some minor differences.
My solution is taken from this comment: https://stackoverflow.com/a/7660915/14163073
So are both of these solution working in accordance with the comment? (operator returns true if at least one item on the left side "matches" one item on the right side)
Thanks for any explanation!
Well, take a tour through an XPath tutorial, I would say. Preferences are often a personal choice and style. For the last test I would simply use e.g. <xsl:if test="mods:namePart = 'foo'"> as that works for any contents of the mods:namePart elements. It doesn't really matter for your simple example but in the end you might end up using XPath against e.g. some mixed contents HTML paragraph element and want to check its whole content (e.g. test="p = 'This is an example text.'") and the p could be anything from a simple <p>This is an example text.</p> to <p>This is an <b>example</b> text.</p>.
Related
I'm using the Maven docbkx plugin to generate a PDF.
I would like the figures to be numbered as usual sequentially from 1, ignoring any chapters, sections etc.
This doesn't work, as I turned on hierarchical numbering of sections with the configuration parameter sectionLabelIncludesComponentLabel in the pom.xml. Now the first section in chapter 2 is not 1 (as it is by default) but 2.1, as I want.
But as a side effect, the first figure in chapter 2.1 gets the number 2.1, too, and the next figure gets 2.2, so the chapter number is not only prepended to sections, but also to figures (which makes absolutely no sense).
How can I have hierarchical section numbers, but at the same time simple sequential figure numbering?
[Edit]
Looks like sectionLabelIncludesComponentLabel has nothing to do with it. Even if I turn it off, the figure titles are prefixed with the chapter number.
There is no parameter to switch on the wanted behaviour, but it can be done by customizing a template in common/labels.xsl (the number part of a title is called a "label" in DocBook-XSL).
You will need to create a customization layer and add the following to it:
<xsl:template match="db:figure" mode="label.markup">
<xsl:choose>
<xsl:when test="#label">
<xsl:value-of select="#label"/>
</xsl:when>
<xsl:otherwise>
<!-- Use simple sequential numbering within a book -->
<xsl:number format="1" from="db:book" level="any"/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
I am trying to do some cleanups using XSLT. I want to do some changes on text fragments and leave all the other nodes in peace. However my current implementation runs very slow and consumes a lot of memory. The removal of a small template changes the run time from a minute to a fraction of a second.
This is the XSLT:
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
<xsl:import href="../common/identity.xsl"/>
<xsl:template match="text()" priority="100">
<xsl:variable name="pass1" select="replace(., '(_|~)', ' ')"/>
<xsl:variable name="pass2" select="replace($pass1, ' , ', ', ')"/>
<xsl:variable name="final" select="$pass2"/>
<xsl:value-of select="$final"/>
</xsl:template>
<xsl:template match="body/text()[1][. = ' '] | body/text()[last()][. = ' ']"
priority="200"/>
</xsl:stylesheet>
The first template replaces some characters, the second template removes the first and last text fragments, but only if they contain exactly one space (sadly normalize-space does not fit my needs).
This XSLT runs very slow and consumes a lot of memory. If I remove the last templates, the same XSLT runs fast and using a normal amount of memory.
The XSLT is run using Saxon-(HE|EE) 9.5.1.3 inside oXygen 15.2.
What is causing this big loss of performance? Is it the use of text fragments in general? The use of priorities? The use of [1] and [last()]?
using not(following-sibling::text()) instead of last() fixed it. Could you explain why or give some pointers to the problems of last()?
There are two ways of evaluating patterns: left-to-right, and right-to-left, corresponding to the "formal" and "informal" semantics given in section 5.5.3 of the specification. The right-to-left method is much more efficient, but it cannot be used for all patterns; in particular, patterns that use positional predicates are tricky. Saxon will handle a number of cases efficiently, including match="para[last()]", but for some others, including match="para[last()-1]" and (it seems) match="section/para[last()]", it takes the slow-but-methodical route. I'll take a look at the code and see if this can be improved.
when I output the value of the node directly for example:
<fo:inline><xsl:value-of select="isEnabled" /></fo:inline>
I get the correct string outputted in pdf "true"..
but if I set the value of isEnabled directly to a variable and then try to do the comparison on it.. it doesn't seem to work as if the node doesn't exist.
<xsl:variable name="isEnabled" select="isEnabled" />
<xsl:choose>
<xsl:when test="$isEnabled = 'true'">
dostuff...
It seems that the value is never received correctly here and the test always fails
Any ideas?
Does isEnabled contain whitespace?
<isEnabled>true</isEnabled>
vs.
<isEnabled>true </isEnabled>
or
<isEnabled>
true
</isEnabled>
will give different results for your test. The first one should pass, the next two likely will not. Yet, they may all appear to render as the text "true" when using value-of.
How about?
<xsl:variable name="isEnabled">
<xsl:value-of select="isEnabled" />
</xsl:variable>
<xsl:when test="normalize-space($isEnabled)='true'">
ok turned out it wasn't an xsl issue but the problem is much earlier.. at the velocity template that generates the xml for the transformation. How can I close this question?
A project I'm working on involves 3 distinct systems/platforms. C#, Java, and XSLT. I have some simple algorithms (just a bunch of conditionals), expressed in pseudo-code as something like:
if inputParameter1 is equal to 1
return "one"
else if inputParameter2 is equal to 5
return "five" concatenated with inputParameter1
else
return "not found"
simple stuff like that.
I'm trying to figure out a mechanism that will:
Let me write the algorithm once
Be able to execute the algorithm in the native language of each system (C#, Java, and XSL)
Have each system (C#, Java, and XSL) always use the latest version of the algorithm when the algorithm is updated.
So to elaborate on my example, the C# representation would be:
public string TheMethod(int inputParameter1, int inputParameter2)
{
if (inputParameter1 == 1)
{
return "one";
}
else if (inputParameter2 == 5)
{
return string.Concat("five", inputParameter1.ToString());
}
else
{
return "not found";
}
}
and the XSLT representation would be:
<xsl:template name="TheMethod">
<xsl:param name="inputParameter1" />
<xsl:param name="inputParameter2" />
<xsl:choose>
<xsl:when test="$inputParameter1 = 1">
<xsl:text>one</xsl:text>
</xsl:when>
<xsl:otherwise>
<xsl:choose>
<xsl:when test="$inputParameter2 = 5">
<xsl:text>five</xsl:text>
<xsl:value-of select="$inputParameter1" />
</xsl:when>
<xsl:otherwise>
<xsl:text>Not Found</xsl:text>
</xsl:otherwise>
</xsl:choose>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
hopefully you get the idea.
How would I express an algorithm in a generic way and be able to automatically convert it to C#, Java, or XSL?
Thanks!
-Mike
Well, the "answer" to this is a DSL, or just some common markup that you then render (amusingly, you could do this with XSLT).
But generally, IMHO, implementing this isn't worth the trouble, depending on how complicated your algorithm is and how many of them you'll be writing.
Looking at this problem a little more generally, your aim is to have only one authoritative version of the algorithm (i.e. the "Don't Repeat Yourself" principle).
Instead of trying to automatically translate/export to different programming languages, a simpler solution would be to choose one language (probably XSL) to implement the algorithm. Then in C# and Java just use some XSL tools to execute the algorithm directly, passing in whatever parameters you like. I haven't done this before, but I assume it is possible with the right third-party tools (whereas I doubt you could do it the other way around, executing Java or C# from within XSL, which is why XSL is the best choice for the "base" language).
This does not produce a source code, but it make possible to use the logic in various languages with very little coding:
Write a simple xml like this:
...
<case>
<InputParam1>1</InputParam>
<InputParam2>NULL</InputParam>
<answer>one</answer>
</case>
...
Then parse it, and store it in a dictionary/map/whatever-the-language-or-framework-has-for-hashtables. So, store the inputparams as the key (perhaps, as a sturct), and you get the answer very quickly. For the cases when the parameters itselves are used in the return value (like in your example in the "concat part"), I'd use some special syntax for the data like
...
<answer>five$inputparam1$</answer>
...
It is worth mentioning that the more special cases you have, like this concatenation, the less useful this solution can be.
Can anyone please suggest an XPath expression format that returns a string value containing the concatenated values of certain qualifying child nodes of an element, but ignoring others:
<div>
This text node should be returned.
<em>And the value of this element.</em>
And this.
<p>But this paragraph element should be ignored.</p>
</div>
The returned value should be a single string:
This text node should be returned. And the value of this element. And this.
Is this possible in a single XPath expression?
Thanks.
In XPath 2.0 :
string-join(/*/node()[not(self::p)], '')
In XPath 1.0:
You can use
/div//text()[not(parent::p)]
to capture the wanted text nodes. The concatenation itself cannot be done in XPath 1.0, I recommend doing it in the host application.
/div//text()
double slash forces to extract text regardless of intermediate nodes
This look that works:
Using as context /div/:
text() | em/text()
Or without the use of context:
/div/text() | /div/em/text()
If you want to concat the first two strings, use this:
concat(/div/text(), /div/em/text())
If you want all children except p, you can try the following...
string-join(//*[name() != 'p']/text(), "")
which returns...
This text node should be returned.
And the value of this element.
And this.
I know this comes a bit late, but I figure my answer could still be relevant. I recently ran into a similar problem. And because I use scrapy in Python 3.6, which does not support xpath 2.0, I could not use the string-join function suggested in several online answers.
I ended up finding a simple workaround (as shown below) which I did not see in any of the stackoverflow answers, that's why I'm sharing it.
temp_selector_list = response.xpath('/div')
string_result = [''.join(x.xpath(".//text()").extract()) for x in temp_selector_list]
Hope this helps!
You could use a for-each loop as well and assemble the values in a variable like this
<xsl:variable name="newstring">
<xsl:for-each select="/div//text()">
<xsl:value-of select="."/>
</xsl:for-each>
</xsl:variable>